Fix python-poetry#3520

poetry/utils/env.py

@@ -440,9 +440,31 @@ def activate(self, python: str, io: IO) -> "Env":
 
         try:
             python_version = Version.parse(python)
-            python = f"python{python_version.major}"
+            python = f"{python_version.major}"
             if python_version.precision > 1:
                 python += f".{python_version.minor}"
+            if sys.platform == "win32":
+                # Use Python Launcher for Windows to retrieve the path of the Python executable.
+                python = "-" + python
+                python = (
+                    '"'
+                    + decode(
+                        subprocess.check_output(
+                            list_to_shell_command(
+                                [
+                                    "py",
+                                    python,
+                                    "-c",
+                                    "\"import sys; print(f'{sys.executable}', end='')\"",
+                                ]
+                            ),
+                            shell=True,
+                        )
+                    )
+                    + '"'
+                )
+            else:
+                python = "python" + python
         except ValueError:
             # Executable in PATH or full executable path
             pass